you're over simplifying it. Its not just volume. If you listened to Grupe, he talks of Rizzi being fully connected to the players as individuals and there's complete transparency. Players always know where they stand and because of that will play hard for the coach. Id suspect Campbell is the same way. With that said, its clear that Kellen Moore will be the coach, because if he wasn't then the Saints themselves would've announced it, and would've freed up KM from the grilling hes taking during a period where he needs to be locked in on the SuperBowl.